There has been an on-going effort to reduce the cost of making containers. Efforts have been made to reduce the amount of materials used to make the containers. With respect to dispensing containers having an orifice in a substantially rigid upper portion that is joined to a body portion, e.g., collapsible dispensing containers having and orifice in a substantially rigid head whose shoulder is joined to a squeezable or collapsible body, efforts have been directed to reducing the thickness of the upper portion or head. However, these efforts have met with only limited success. When the thickness of the upper portion, e.g., the portion of the shoulder of the head that is joined to the upper end portion of the body, has been reduced, the bond at the joint between the shoulder and the body has lacked sufficient strength to maintain the integrity and seal of the joint. One problem has been that with a thinned shoulder, there has not been an effective way to provide enough plastic material of the shoulder at a high enough temperature to and at the area of the joint with the upper portion of the body wall, to obtain an effective joint and seal. For example, in injection molding processes that inject heads from or through the rim of the orifice of the head to the portion, usually the lower, portion of the shoulder, the temperature of the thinned plastic material drops as it travels through the mold cavity to the area of the shoulder where the temperature of the plastic is not high enough to form a satisfactory bond to the body wall. Although the injection gate can be towards the shoulder to shorten the travel and achieve the bond, it makes it more difficult to back fill the head without flashing the shoulder joint.
It would be desirable to provide low cost containers, especially of the collapsible dispensing type, that employ less materials to produce and that have sufficient strength and integrity. It would also be desirable to provide improved methods and apparatus for forming such containers.
It is an object of this invention to provide improved low cost containers of the above-described type, and methods and apparatus for forming them, that overcome one or more of the above-described problems and/or meet one or more of the above mentioned desires.